BACHER, ROBERT FOX (1905–2004), U.S. physicist. Born in Loudonville, Ohio, Bacher joined the staff of the Massachusetts Institute of Technology in 1932. After teaching at Cornell University for a time, he returned to MIT as a research associate in the radiation laboratory. During World War II he worked on the bomb project at the Los Alamos laboratory, and he became head of the bomb physics division. He was a member of the Atomic Energy Commission from 1946 to 1949. He was then appointed professor of physics at the California Institute of Technology, heading the Mathematics, Physics, and Astronomy Division. He retired in 1976.